Installing Backend Nodes

Each static backend is a worker that registers with the gateway, hosts a Windows session pool, and streams applications. Install every node with the same interactive WebStream ACP installer used for the gateway, in Backend Only mode.

Prerequisites

Gateway node installed and reachable on its private IP (ports 9000 and 9009). See Installing the Gateway Node.
The gateway’s internalApiKey from INSTALL-NOTES.txt.
Security groups configured so the backend can reach the gateway and the gateway can reach the backend. See AWS Security Groups and Ports.
Applications and dependencies you intend to stream, installed on this host (or baked into an AMI later).

Wizard steps (per node)

Run WebStreamACP-Setup-<version>.exe as Administrator. Install directory default: C:\WebStream.
On Installation Mode, select:
Backend Only - Worker server that connects to an existing Gateway.
On Session Pool Users, enter the number of Windows pool accounts (5–25, default 5). Accounts are named webs01…websNN. This sizes the local pool; live capacity is later clamped by Max Sessions and the licence AbsoluteMax.

On Gateway Connection Details, complete:

Field	Guidance
Gateway IP / Hostname	Required. Use the gateway’s private IP or DNS name inside the VPC.
Gateway Port	Default `9000`.
Max Sessions	Defaults to the pool size. Must be an integer from 1 to the pool size.
Backend Tags	Optional. Comma-separated tokens such as `gpu,gp3,spot`. Letters, digits, hyphen, underscore; must start with alphanumeric. See Backend Tags and Placement Bias.
Internal API Key	Paste the gateway key. The wizard probes the gateway; leave blank only if you accept that preference roaming will fail until you set it.

Choose a client theme if prompted. The Isolation Features page appears for Backend mode (filesystem hive is off by default).
Complete post-install steps 1, 3, and 4. Step 2 (SSL certificate) is hidden for Backend mode — backends speak plain HTTP on the private network.

Step 3 runs setup-server.ps1 -InstallMode Backend -UserCount N -ConfigureAll -Force, which creates the pool accounts, Windows Firewall rules (9005 and the streamer range), and RDS/GPO settings for the pool.

Repeatable scripted path (nodes 2…N)

The interactive installer has no silent Backend mode switch. For additional nodes you can copy files with a silent install, then reconfigure:

C:\WebStream\Scripts\Configure-Config.ps1 -InstallDir C:\WebStream -InstallMode Backend `
  -GatewayIP 10.0.1.10 -GatewayPort 9000 -MaxSessions 25 -BackendTags "gpu,cad" `
  -InternalApiKey "<from gateway INSTALL-NOTES.txt>" -Theme Dusk -FilesystemHiveMode disabled

C:\WebStream\Scripts\setup-services.ps1 -InstallMode Backend
C:\WebStream\Scripts\setup-server.ps1 -InstallMode Backend -UserCount 25 -ConfigureAll -Force
C:\WebStream\Scripts\setup-complete.ps1

Note

A bare /SILENT run of the interactive installer defaults to Single mode and skips post-install steps. Always follow with the script chain above when automating Backend nodes.

Per-node verification checklist

Check	Expected
`Get-Service Webstream-Backend`	Running. No Gateway/Metrics/Access services required on a dedicated backend.
Pool accounts	`webs01`…`websNN` exist as local users.
Windows profiles	Each account has `C:\Users\<name>\NTUSER.DAT`. An account with no profile fails RDP logon (MSTSC `-5`) and silently costs a session slot. Re-run `provision-session-pool.ps1` if any are missing.
`accessManagement/internalApiKey`	Identical non-empty value to the gateway.
Firewall	Rules for Backend (9005) and Streamers (`9010` through the pool end port). See the security-groups page for the 25-session range.
`GET /gateway/stats` on the gateway	This node appears with the expected `maxSessions` and `tags`.
Effective capacity	`min(config maxSessions, licence AbsoluteMax)`. Drive concurrent sessions up to Max Sessions so every pool account is exercised, not only `webs01`.

Tip

Testing with a single session only ever uses the first pool account. Missing profiles on webs02… stay hidden until concurrency forces them into use.

Config written for Backend mode

gateway/backend/gatewayUrl — http://<GatewayIP>:<GatewayPort>
gateway/backend/advertisedUrl — this host’s URL on port 9005 (auto-detected if blank at startup)
gateway/backend/maxSessions and webstreamSettings/serverMaxSessionCount
gateway/backend/tags — from the wizard or -BackendTags
accessManagement/internalApiKey — from the wizard (not generated on Backend)